In 1979, Walter was an editor with Alfred van der Marck Editions. He began to work on several projects with Campbell, who subsequently named him editorial director of his Historical Atlas of World Mythology.[4][5]

Volume I: The Way of the Animal Powers (1983) (reprint in two parts: Part 1: Mythologies of the Primitive Hunters and Gatherers (1988);Part 2: Mythologies of the Great Hunt (1988))

Volume II: The Way of the Seeded Earth (Part 1: The Sacrifice (1988); Part 2: Mythologies of the Primitive Planters: The North Americas (1989);Part 3: Mythologies of the Primitive Planters: The Middle and Southern Americas (1989))

Transformations of Myth Through Time (1990)

A Joseph Campbell Companion: Reflections on the Art of Living (1991). editor Diane K. Osbon

Mythic Worlds, Modern Words: On the Art of James Joyce (1993). editor Edmund L. Epstein